A simplified method for determining earthquake early warning thresholds in high speed railways

Area of Science:

• Civil Engineering
• Geotechnical Engineering
• Railway Engineering

Background:

• High-speed railways face significant risks from seismic events.
• Existing earthquake early warning systems lack specific thresholds for railway safety.
• Understanding derailment dynamics under seismic action is critical for infrastructure protection.

Purpose of the Study:

• To determine reliable earthquake early warning thresholds for high-speed railways.
• To investigate the influence of track irregularities and seismic actions on train derailment.
• To propose a novel method for calculating early warning thresholds.

Main Methods:

• Validation of a 2D vehicle-track numerical model using shaking table test data.
• Analysis of track irregularities' impact on derailment risk under seismic loads.
• Superposition analysis of track irregularities and seismic effects to reveal derailment patterns.
• Calculation of early warning thresholds using a 2D model with six different seismic waves.

Main Results:

• Track conditions, not vehicle speed, are more critical for derailment risk during earthquakes.
• Superimposed effects of track irregularities and seismic action dictate train derailment patterns.
• A novel method for deriving earthquake early warning thresholds has been successfully applied.

Conclusions:

• The study provides a new theoretical basis for high-speed railway earthquake early warning systems.
• The proposed method offers practical guidance for designing and implementing effective railway safety systems.
• Accurate early warning thresholds are essential for mitigating seismic risks in high-speed rail operations.